Method of manufacturing glass reflectors



May 15, 1934. c. R. PALMER ET AL METHOD OF MANUFACTURING GLASS REFLECTORS I Filed July 21, 1951 2 Sheets-Sheet y 1934. c. R. PALMER ET AL METHOD OF MANUFACTURING GLASS REFLECTORS INVgNTORS. Carl 1? Pa Car/ E Anderson BY ATTORNEY.

Filed July 21, 1931 Patented May 15, 1934 UNITED STATES PATENT OFFICE Carl R. Palmr and Carl E. Anderson,

Steubenville, Ohio Application July 21, 1931, Serial No. 552,090

1 Claim.

This invention relates to glass reflectors to be used in conjunction with an illuminating device such as an electric light bulb, and to a method of and apparatus for manufacturing the same.

An object of our invention is to provide a novel reflector of the class described, capable of use with an illuminating device or element, and capable of extremely long life without diminution of reflecting power and brilliancy. Y

A further object of our invention is to provide a method of manufacturing a reflector of the class described and as further set forth and described hereinbelow, and apparatus for use in conjunction therewith, which method and ap paratus are such as to enable the reflector to be made in a simple and efficient manner.

Our invention 'has for further objects such other advantages and improvements as may be hereinafter found to obtain.

Glass reflectors for use with illuminating elements or lamps, as made according to the prior art, have been of such character as to lose their brilliance after a comparatively short period of use, especially when used in exposed positions, and have been relatively weak in structure, resulting in frequent breakage.

According to our invention, we provide a reflector, of suitably dished or concave configuration, with provision for the insertion of an electric light bulb or similar illuminating element through the same, and having double walls, the interior surface of which are silvered, and having the interior portions between the walls sealed to prevent access of air or the elements.

In manufacturing our reflector, we provide for forming a depression at the point where the opening for the bulb is to be located. This depression aids in the silvering process, serves to form a retaining ledge for the sealing material, and enables the subsequent cutting of the bulb-insertion orifice to be accomplished more easily and with improved results than would be true if the depression were omitted.

For the molding, blowing, or manufacture of our reflector, we provide a mold having separable outer walls to permit the insertion of a ball or gob of glass on the end of the glass blowers pipe, and a movableplug which is then used to bring the glass to the proper shape while blowing, and which is provided with a shoulder suitably located and designed to provide the desired depression in the wall of the reflector.

In order that our invention may be fully set forth and understood, we now describe preferred forms in which ,.our invention may be practiced and embodied, with reference to the accompanying drawings forming a part of the specification, In these drawings,

Figure 1 is a sectional view of a reflector made in accordance with our invention; 5

Fig. 2 is a view, partly in elevation and partly in cross-section, of our reflector in an intermediate stage of manufacture;

Figs. 3 and 4 are side elevational views of a mold constructed in accordance with our inven-. tion for manufacturing the. reflector illustrated in Figs.1 and 2;

Fig. 5 is a similar view of the-mold illustrated in Figs. 3' and 4, shown in an open position; and

Fig. 6 is a perspective view of the mold ready for use, showing auxiliary equipment useful therewith.

Similar reference numerals, designate the same or similar partsin each of the views of the drawings.

As shown in Fig. 1, ourreflector comprises a glass structure having an inner concave reflecting wall 1 and an outer wall 2, spaced therefrom, the walls 1 and 2 being continuously joined at the periphery of the structure and the outer wall 2 being preferably, although not necessarily, of a configuration generally similar to that of the inner wall 1, with respect to a large portion or all of the reflecting portion of the latter.

' The outer wall 2 is provided with an annular neck 3, preferably located on an extension of the principal axis of the walls 1 and 2. The neck 3 is preferably provided with a lip 4"adapted to assist in retaining the reflector when inserted within a clamping socket 5 having positioning screws 6, or with some other form of retaining means.

When so positioned, the neck 3 encloses a socket '7 or other holding element for an electric light bulb 8 or whatever illuminating element is to be employed.

The inner wall-'1 is provided with an annular ring or shoulder 9','located coaxially with the neck 3, and forming an opening 10 through which the bulb 8 is inserted.

The inner sides of the reflecting wall 1 and preferably also the inner sides of the wall 2 are silvered or otherwise provided with a suitable reflecting coating, while an annular ring 12 of sealing material, such for example as plaster-of- Paris, is provided between the annular ring 9 and the neck 3, thus hermetically sealing the space 13 between the inner wall 1 and the outer wall 2.

In Fig. 2, the reflegtor is shown in an intermediate stage of manufacture, that is to say just after it has left the mold and the end of the neck 3 has been cut off. In this stage, the ring 9 terminates in a depressed portion or shoulder 14, preferably located within the neck 3. The shoulder 14 serves to assist in the silvering of the inner surfaces of the walls .1 and 2, after which it is cut oil to provide anopening through the reflector for the bulb 8.

In manufacturing our, reflector, we prefer to employ the mold shown in Figs. 3 to 6, inclusive, which constitutes a part of our invention. Although it will be obvious to those skilled in the art that molds of other types may be employed in the manufacture of our reflector, nevertheless our improved mold is of especial advantage with respect to the manufacture of our reflector.

As shown in Figs. 3, 4 and 5, the mold is provided with two upper half-sections 16 having handles 1'7 and being pivotally attached by hinges 18 located at opposite portions of an annular base 19 upon which the sections 16 rest when in the closed position as shown in Figs. 3 and 4. To the bottom of the base 19 is attached a cross piece 21 having a collar or bearing 22 through which passes a vertically movable rod 23 carrying a plug 24 of external shape corresponding to the configuration of the inner wall 1 of the reflector shown in Fig. 2. To the base 19-is attached a collar or bearing 25, through which passes a rod 26 terminating below the base of the mold in a horizontal member 27 adapted to engage movable clamps 28 and 29 fastened on the rod 23.

Thus, raising or lowering the rod 26 effects a raising or lowering, as the case may be, of the rod 23 and plug 24. In the upper position of the plug 24, there is left a space between the same and the upper sections 16 correspondingto the configuration-of the'refiector shown in Fig. 2. while provision is thus made for lowering the plug a short distance, for example, four or five inches, depending upon the size of the reflector to be made.

The plug 24 is provided with a raised portion sections 16 are provided with half-circular neck portions 32, thus providing an opening to receive the glass-blowers pipe.

, The walls of the mold may be provided with a number of holes for the purpose of cooling the mold and allowing steam to escape, and the inner walls of the sections 16 and the plug 24 are preferably covered with a suitable paste, such as a paste made from linseed oil and fine charcoal.

In use, the mold is supported upon a bracket 40 or other supports in the upper part of a pail 41 or other receptacle for water, which is used to cool the mold. The mold is held above the level of the water by the bracket 40, with the upper portion of the mold above the top of the pail 41. The pail 41 is located alongside of a dummy or bench 42 having a support 43 to which amount of molten glass on the end of his pipe,

and places it over the plug 24. He then presses the glass down over the plug 24 while blowing. The upper sections 16 are then closed, and the glass-blower continues to blow, while slowly elevating the plug 24 by means of the lever 44, and rotating the pipe and the glass attached to it, in order to insure a smooth surface.

After the blowing has been completed and the glass has cooled, the mold is opened and the reflector is removed. The neck is then cut off in the usual manner, and the interior of the reflector is silvered. The shoulder portion 14 is then cut oil preparatory to scaling the reflector.

The reflector is then sealed with plaster-of- Paris or other suitable material, and a metal ring 50 is then attached to the interior of the neck 3, to cover the plaster-of-Paris seal leaving the reflector ready to be used.

It will be obvious that our reflector is' adapted for use in many instances, especially where the reflector is exposed to the air, where our reflector will have an eflicient life far in excess of other reflectors. It may be employed, for example, in a trafiic light, in an automobile headlight, or in a lighting fixture for any purpose.

Where the reflector is to be used in an automobile headlamp or a trafilc signal, the neck 3 may be made shorter or cut off, and a rubber ring substituted for the clamping socket 5.

It will be obvious to those skilled in the art that our invention is not limited to the specific details of the illustrative examples described hereinabove or in the drawingsbut may variously be practiced and embodied within the scope of the claim hereinafter made.

We claim as our invention:

The method of manufacturing a hollow glass reflector shell of the character described, which comprises rotating a mass of plastic glass within a paste-lined mold of initially larger internal size than that of the finished article desired in such manner as to rotate all parts of the glass with respect to the mold, while blowing air into the rotating mass of glass to force the same against the walls of the mold, contracting the mold while the mass of glass is rotated in a plastic state to compress the glass to the size of the article desirell, cooling the glass in the mold until the glass is no longer plastic, and finally removing the thereby hardened article from the mold.

CARL R. PALMER. CARL E. ANDERSON. 

